The present invention relates to a self-sealing catheter valve including                a flexible tubular part having a distal opening and an opposite proximal opening, and        a proximal valve part that has a curved self-sealing flexible diaphragm disposed inside the flexible tubular part and has a base perimeter united with a circumferential wall of the flexible tubular part,        the curved self-sealing flexible diaphragm has a concave surface facing towards the proximal opening and a convex surface facing towards the distal opening, and 1a flexible diaphragm wall of the curved self-sealing flexible diaphragm has a traverse slit.        
The conventional peripheral catheter which is used all over the world has a tip for insertion into the blood vessel, wings for manual handling and securing the catheter with adhesives, a valve to allow injection of drugs with a syringe, and an end which allows connection to an intravenous infusion line or allows capping in between uses. A needle serves as a “guidewire” for inserting the catheter into the vein.
US patent application no. 2013/090607 discloses an alternative intravenous catheter with a catheter adapter that includes a valve. The valve serve the dual function of a selectively sealing both an infusion port and the internal lumen of the catheter adapter. The valve is a duckbill valve, which includes two inwardly oriented flaps, which are biased together toward a central position, forming a slit. These flaps can extend from a tube portion of the valve inwardly and distally to be pushed together to close the valve in response to a fluid flow in a proximal direction towards the distal end of the catheter adapter. Additionally, the two inwardly oriented flaps can be pushed apart to open a gap between these flaps in response to a fluid flow in a distal direction. The duck bill design with straight flaps that delimit the traverse slit are not compatible with opening and closing of concave and convex membrane surfaces.
U.S. Pat. No. 5,456,284 discloses a different duckbill valve without a curved self-sealing flexible diaphragm disposed inside the flexible tubular part. This known duckbill valve features a cat-eye effect, albeit this effect is alleged reduced. Even the smallest cat-eye effect causes undesired leakage of the valve of this known duckbill valve.
U.S. Pat. No. 3,889,675 relates to a disposable suction-irrigating instrument for delivering sterile fluid and applying suction to an operating work area. The instrument includes a valve assembly having a part of its length exposed for contact by the fingers of the operator for controlling the supply of the fluid delivered by the instrument. The valve assembly comprises a resilient tubular connector, a diaphragm integral with and mounted across the bore of the connector, and a slit in the diaphragm having sides that normally abut each other to thereby close the bore but which are spread apart and permit passage of fluid upon application of and deformation of the diaphragm by pressure against the outside of the connector from the operator's fingers. Valves that require the operator to use his/her fingers from outside the valve is not part of the present invention.
U.S. Pat. No. 5,269,763 relates to a cross-slit valve. Cross-slit valves suffers from the disadvantage of having too many degrees of freedom when it come to closing the web members of adjacent lips of the cross-slit arrangement after an inserted objects has been removed. The web members of adjacent lips intersect each other along web intersection lines and each of the intersection lines extend radially inwardly in a direction from the inlet to the outlet end of the valve body thereby defining a valve without concave and convex membrane surfaces.
Applicant's International patent application no. WO 2009 016184 relates to another kind of peripheral catheter assembly having precautionary means for avoiding spillage of blood during insertion and during infusion. To that aspect applicant's peripheral catheter assembly comprises a sealing valve having a septum seal. The septum seal has deflectable septum walls, and a hollow tubular extension which protrudes towards a free end from the periphery of the septum seal and extends inside the catheter hub past the injection port towards the distal end of the catheter hub to provide a self-closable sealing member which provides the physician the freedom to leave the patient when the needle module is retracted. It has however now been realised that although the sealing valve described in WO 2009 016184 has many advantages, it's sealing properties deteriorates too fast, in particular sterilizing sometimes alters the sealing valve's sealing properties to an extent that the sealing valve may leak, e.g. during the insertion procedure.
U.S. Pat. No. 4,436,519 relates to an alternative kind of valve, namely a hemostasis valve comprising a dome-shaped diaphragm wall member with a securing flange. The dome-shaped diaphragm wall has a diaphragm slit opposite the flange. This narrow small slit can open to allow passage of an inserted catheter. Upon forcing the catheter through the diaphragm slit, a diaphragm rib compresses against an upper central passage wall of a special house fitting. Upon withdrawing the catheter from the hemostasis valve the compressed diaphragm rib expands to its original position, causing the diaphragm slit to close. The exterior face of the hemostasis valve fits tightly into an assembly of plural parts, the special house fitting, including various connectors, extra seals, caps and fasteners that when assembled keep the hemostasis valve in fixed position of use when a needle is introduced into a blood vessel via the rather deep valve chamber defined by the cavity of the dome. A male Luer coupling cannot be inserted through the slit of the dome, nor is such intended or described in U.S. Pat. No. 4,436,519.
Thus there is still a demand between physicians and medical staff for improved sealing valves for peripheral catheters that makes catheter insertion easier, safer and more reliable.